Leveling system for a playing surface

ABSTRACT

Apparatus and system for leveling a playing surface on a table, such as a billiards or pool table, which utilizes a plate which supports the playing surface and which is tiltable about an x and y-axis for maintaining contact with the playing surface regardless the angle of the surface relative to the frame. Further, the apparatus is height adjustable to assist with leveling the playing surface in engagement with the plate of the leveling apparatus. Leveling apparatus are also provided between the legs of the table and the frame and which can be pre-leveled before positioning the playing surface to minimize the amount of leveling required to level the playing surface relative to the frame.

FIELD OF THE INVENTION

Embodiments of the invention relate to systems for leveling a playing surface of a table and more particularly to apparatus for leveling a playing surface, such as a billiards table.

BACKGROUND OF THE INVENTION

A variety of playing surfaces require leveling in order to permit proper movement of playing pieces thereon. Certain games, such as billiards and pool and the like, are very sensitive to proper leveling in order to fairly allow the balls to travel on the surface.

In most tables used for billiards, a wooden frame is supported on a plurality of legs and a playing surface, such as slate, is supported on the wooden frame. The slate surface may be provided in a single piece or in a plurality of pieces which are positioned side by side on top of the frame. Thus, both the leg and frame assembly may be off-level as can be the slate or portions of the slate. Leveling therefore becomes complex.

Conventionally, leveling may be performed using shims which are placed below the table legs and/or between the slate and the frame. Due to the weight of the entire assembly, lifting the entire table or even portions of the slate is difficult and may be very time consuming. Positioning of the shims requires much trial and error.

Alternately, Applicant is aware of externally threaded leveling feet which are attached to a lower surface of each of the table legs for leveling the table. Typically, the area of contact between the leveling foot and the floor is reduced and there is difficulty in handling the weight of the table while adjusting the height of the leveling feet.

Many have attempted to provide solutions to the problem of leveling.

U.S. Pat. No. 1,860,215 to Young teaches screws having swivel plates attached to one end and flattened wings attached to the other for raising and lowering support bars which extend lengthwise under the bed within the outer frame of the table for raising and lower the bed during leveling.

U.S. Pat. No. 3,658,328 to Kooker teaches vertically extending leveling screws which extend between a cast concrete pedestal and a cast concrete top of the table for adjusting the level thereof.

U.S. Pat. No. 4,027,878 to Dadbeh teaches support bars mounted transversely within the frame for supporting the bed and bed-level slide brackets slidably mounted on the support bars for movement therealong to a plurality of positions beneath the bed. An adjusting mechanism, which incorporates a threaded screw and a flat head attached thereto, is connected to the bracket for adjusting the level of the bed.

U.S. Pat. No. 5,161,797 to Frasca teaches leveling means used between the table legs and the table frame and leveling means between the table frame and the slate. A head of the adjustable rod used between the slate and the table is embedded in the slate top and is supported to extend vertically upward from the frame by an angle bracket affixed thereto.

U.S. Pat. No. 5,839,966 to Eisenhauer et al teaches slate levelers having a threaded shank received in an associated nut in a radially outwardly directed flange at one end of the shank at an interface between the top plate of the table and the slate sheets and engages the slate sheets for adjustable leveling. The flange is rigidly connected to the shank. The levelers are positioned about a periphery of each sheet of slate.

U.S. Pat. No. 6,132,320 to Spoerl et al teaches externally threaded support rods having a collar threaded thereon a support member upon which the playing surface rests and a fastener for securing the apparatus to an underlying surface.

In all cases where leveling occurs between the table and the slate, the prior art apparatus provide a rigid contact surface for engaging the slate, thus the apparatus may not remain fully in contact with the slate.

Clearly there is interest in apparatus for reliably and securely leveling playing surfaces to ensure proper movement of playing pieces, such as balls, thereon.

SUMMARY OF THE INVENTION

Apparatus and a system for leveling a playing surface using at least said apparatus enable leveling of the playing surface with reduced point loading on the playing surface to prevent damage thereto.

In a broad aspect of the invention, apparatus for leveling a playing surface supported in a frame comprises: a bracket for connection to the frame; a threaded member supported in the bracket and extending axially upwardly therethrough, an effective height of the member being adjustable axially along a z-axis within the bracket; and a contact plate for supporting the playing surface thereon in a substantially level orientation, the contact plate supported at a top end of the threaded member for tilting about an x-axis and a y-axis, the plate being moveable thereabout for freely orienting the contact plate relative to an underside of the playing surface so as to substantially maintain distributed contact with the playing surface when the effective height of the threaded member is adjusted to position the plate at the underside of the playing surface.

Preferably, the contact plate is connected to the threaded member through a ball and socket type connection. The apparatus are connected to the frame supporting the playing surface about the periphery of the playing surface avoiding supporting the playing surface from cross-members which may be susceptible to warping and the like.

In a further broad aspect of the invention, a system for leveling a playing surface supported in a frame having a plurality of legs for supporting the frame, the system comprises: apparatus for leveling the frame on the plurality of legs, each leg leveling apparatus comprising: one or more externally threaded rods connected between the leg and the frame for supporting the frame thereon, each of the one or more rods being axially moveable therebetween for adjustment to an effective height for leveling the frame relative to the leg; and apparatus for leveling the slate relative to the frame, each slate leveling apparatus comprising: a bracket for connection to the frame; a threaded member supported in the bracket and extending axially upwardly therethrough, an effective height of the member being adjustable axially along a z-axis within the bracket; and a contact plate for supporting the playing surface thereon in a substantially level orientation, the contact plate supported at a top end of the threaded member for tilting about an x-axis and a y-axis, the plate being moveable thereabout for freely orienting the contact plate relative to an underside of the playing surface so as to substantially maintain full contact with the playing surface when the effective height of the threaded member is adjusted to position the plate at the underside of the playing surface, wherein the effective height of each of the one or more rods of each leg leveling apparatus are adjusted so as to level the frame supported on the legs; and thereafter, the effective height of the threaded member of each of the slate leveling apparatus is adjusted for leveling the slate relative to the frame.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a partial top perspective view of a table illustrating a system according to an embodiment of the invention for leveling a playing surface, the playing surface having been removed for clarity, the system comprising slate leveling apparatus and leg leveling apparatus;

FIG. 1 b is a detailed perspective view of a leg of the table according to FIG. 1 a illustrating a portion of the leg leveling apparatus;

FIG. 2 is a an exploded top perspective view illustrating an embodiment of the slate leveling apparatus positioned about the frame for supporting a plurality of pieces of the playing surface which are removed and shown ready for installation thereon;

FIG. 3 is a partially exploded view according to FIG. 2, one of the plurality of pieces of playing surface having being installed and supported about a periphery by the slate leveling apparatus;

FIGS. 4 a-4 d are perspective views of an embodiment of the leg leveling apparatus according to FIGS. 1 a and 1 b, more particularly,

FIG. 4 a is a sectional view of a top of a leg illustrating a socket installed therein and supporting a threaded rod through a base plate of a mounting bracket, upstanding portions of a frame mounting bracket having been removed for clarity;

FIG. 4 b is a top perspective view of the leg according to FIG. 4 a, illustrating countersinking of the sockets therein;

FIG. 4 c is a top perspective view of the leg according to FIG. 4 a, threaded rods being installed in the sockets; and

FIG. 4 c is a top perspective view according to FIG. 4 a, the mounting bracket having been installed thereon;

FIG. 5 is a perspective view of the slate leveling apparatus according to an embodiment of the invention;

FIG. 6 is a perspective view of the slate leveling apparatus according to an embodiment of the invention; and

FIG. 7 is a perspective view of the slate leveling apparatus according to FIG. 6 installed on the frame of a table.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Embodiments of the invention are described herein in the context of a billiards or pool table. As one of skill in the art would appreciate, leveling apparatus, according to embodiments of the invention, may be applied to other types of playing surfaces which require leveling to ensure proper play.

Well known in the prior art, as shown in FIGS. 1-3, a billiards table 1 typically comprises a frame 2 supported on legs 3 which are positioned at least at corners 4 of the frame 2. Longitudinal and transverse support members 5 typically extend within the frame 2 to provide structural rigidity thereto and to support the weight of a playing surface 6. In the case of a billiards or pool table 1, the playing surface 6 is typically made of slate or other suitable composite material.

Having reference to FIGS. 2 and 3, the slate playing surface 6 may be installed as a single piece, but is more likely to be installed in a plurality of pieces as shown. A typical eight foot table 1 may have three separate pieces of slate for forming the playing surface 6, the pieces being laid side by side for forming a contiguous surface upon which a fabric, such as felt, is applied. The weight of the slate playing surface 6 for an eight foot table averages from about 250 kg to about 290 kg.

With reference to FIGS. 1-6, and in embodiments of the invention, a leveling system comprises a plurality of slate leveling apparatus 10 positioned between the frame 2 and the slate playing surface 6 and one or more leg leveling apparatus 11, which are positioned between the legs 3 and the frame 2. Thus, the frame 2 can be leveled relative to a surface upon which it is supported and further, the slate playing surface 6 can be leveled to overcome imperfections and the like in the frame 2. In embodiments of the invention, the table frame 2 is leveled first, after which the slate playing surface 6 can be leveled when attached to the pre-leveled frame 2.

In one embodiment, as shown in FIGS. 1-4D, the one or more leg leveling apparatus 11 are used between each leg 3 and the frame 2 to level the frame 2 of the table 1 on the legs 3. Each leg leveling apparatus 11 comprises an externally threaded rod 12 which is extends into a bore 13 formed in a top 14 of each table leg 3. The rod 12 extends axially upwards therefrom for supporting the frame 2. In one embodiment of the invention, best seen in FIG. 4A, at least an internally threaded socket 15 is fit within the bore 13 in the top 14 of the leg 3 for retaining the rod 12 to the leg 3, the rod 12 being axially moveable by rotation therein. A washer 16 is secured to the rod 12 and is countersunk into the top 14 of the leg 3 when the rod 12 is fully engaged in the socket 15. As shown, in one embodiment, a top end 17 of the rod 12 is profiled to permit drivable rotation of the rod 12, using means such as an Allen wrench 18 for engaging the profiled top 17, within the socket 15 for adjusting an effective height of the rod 12 so as to level the frame 2 which is connected thereto. As the rod 12 is rotated, the washer 16 is elevated above the top 14 of the leg 3 for supporting a frame mounting bracket 20 thereon. In one embodiment a lock nut 19 is used to secure the position of the rod 12 once adjusted.

In one embodiment, best seen in FIG. 4D, three leg leveling apparatus 11 are fit in the top 14 of each leg 3, typically in a triangular pattern. The frame mounting bracket 20 is positioned over the rods 12 extending therefrom. Adjustment of the effective height of each of the threaded rods 12 permits the frame 2 of the table 1 supported in the frame mounting bracket 20 which are further supported by the washers 16 of the rods 12 to be pre-leveled on the legs 3 relative to the support surface, typically a floor, before installation of the slate playing surface 6.

The frame mounting bracket 20 further comprises one or more upstanding members 21 to which the frame 2 is secured. In one embodiment, the one or more upstanding members 21 form a corner 22 which complies to the corner 4 of the frame 2, the frame 2 being secured to an outside thereof. The one or more upstanding members 21 of the frame mounting bracket 20 may be formed of a single piece of material, such as metal, which is bent to form the corner 22. The upstanding corner member 21 is then secured, such as by welding, to a lower horizontal plate 23 through which the threaded rods 12 extend and which sits atop the leg 3.

Having reference to FIGS. 1A, 2, and 3, a plurality of the slate leveling apparatus 10 are attached about the frame 2 of the table 1 for supporting the slate playing surface 6. In one embodiment, the slate leveling apparatus 10 are only attached to the frame 2 and not to the longitudinal and transverse members 5 for ease of leveling and to prevent changes in level which may occur as a result of warping of the transverse and longitudinal supports 5. In one embodiment, the plurality of slate leveling apparatus 10 engage the slate playing surface 6 at a portion of a periphery 30 of the slate playing surface 6.

Best seen in FIGS. 5 and 6, each of the slate leveling apparatus 10 comprises a bracket 31 for connection to the table frame 2, the bracket 31 having a flange 32 extending inwardly therefrom and inwardly from the frame 2. The flange 32 supports a threaded member 33 extending upwardly therein for axial movement along a z-axis for adjusting an effective height of the threaded member 33 of the slate leveling apparatus 10. The threaded member 33, typically a bolt, further comprises a contact plate 34 secured at a top end 35 for tilting about an x-axis and a y-axis. In one embodiment, the contact plate 34 is connected to the bolt through a ball and socket connection 36. The contact plate 34 is thus permitted to freely rotate to orient about two degrees of freedom to conform to an underside of the slate when the bolt is threaded to the effective height to engage the plate with the underside 37 of the playing surface 6. Thus, the plate 34 is permitted to remain substantially in distributed contact with the underside 37 of the slate playing surface 6 regardless the angle of the slate playing surface 6 relative to the frame 2. Distributed contact of the plate 34 with the slate playing surface 6 is beneficial as any point loading which may otherwise result in damage to the slate playing surface 6 is thereby reduced.

In one embodiment, shown in FIGS. 5-7, the bracket 31 further comprises a planar attachment plate 38 which conforms to the angle of the frame 2 for connection to an inner side 39 of the frame 2. An upper tab 40 extends outwardly from a top 41 of the attachment plate 38, for fitting substantially parallel to a top edge 42 of the frame 2 for attachment thereto. In one embodiment, the top edge 42 of the frame 2 may be notched to countersink the tab 40 even with the top 42 of the table 1. The bolt-supporting flange 32 extends horizontally outwardly from a face 43 of the attachment plate 38 for positioning the contact plate 34 and threaded member 33, substantially parallel to the top 42 of the frame 2. A support member 44 extends from an edge 45 of the attachment plate 38 for supporting the bolt-supporting flange 32 along an edge 46. In one embodiment, the bolt-supporting flange 32 and support member 44 are formed as a unitary angled member. Further, the tab 40 is unitary to the attachment plate 38.

One or more nuts 50 are threaded onto the threaded member 33, to fix the effective height of the threaded member 33 in the flange 32 and thereby adjust the height of the contact plate 34 relative to the top 42 of the frame 2. A single nut 50 can be welded to the flange 32 or nuts 50,50 can be used above and below the flange 32 for securing the height of the bolt 33 relative thereto.

In one embodiment, wherein the frame 2 of the table 1 is angled inwardly at a bottom 51 of the frame 2, the attachment plate 38 is suitably angled relative to the upper tab 40 to permit mounting the attachment plate 38 flush with the inner surface 39 of the frame 2.

In one embodiment, as shown, slate leveling apparatus 10 are positioned to support each piece of slate 6 at each corner thereof. As the frame 2 of the table 1 has typically been pre-leveled using the leg leveling apparatus 11, little adjustment has to be made to the slate leveling apparatus 10 in order to level the slate playing surface 6 relative to the frame 2.

In one embodiment, an upper surface 52 of the contact plate 34 is concave so as to provide at least two points of contact for the slate playing surface 6 to accommodate imperfections in the slate playing surface 6, thus assisting in providing more even distribution of the load across the entirety of the contact plate 34. 

1. Apparatus for leveling a playing surface supported in a frame comprising: a bracket for connection to the frame; a threaded member supported in the bracket and extending axially upwardly therethrough, an effective height of the member being adjustable axially along a z-axis within the bracket; and a contact plate for supporting the playing surface thereon in a substantially level orientation, the contact plate supported at a top end of the threaded member for tilting about an x-axis and a y-axis, the plate being moveable thereabout for freely orienting the contact plate relative to an underside of the playing surface so as to substantially maintain distributed contact with the playing surface when the effective height of the threaded member is adjusted to position the plate at the underside of the playing surface.
 2. The apparatus of claim 1 wherein the contact plate is connected to the top end of the threaded member through a ball and socket connection.
 3. The apparatus of claim 1 wherein the threaded member is a bolt, the bolt further comprising nuts threaded thereon for fixing the effective height relative to the bracket.
 4. The apparatus of claim 1 wherein the playing surface is one or more pieces of slate and the apparatus are adapted for supporting the one or more pieces of slate at a periphery of the one or more pieces of slate.
 5. The apparatus of claim 1 wherein the contact plate is concave.
 6. A system for leveling a playing surface supported in a frame having a plurality of legs for supporting the frame, the system comprising: apparatus for leveling the frame on the plurality of legs, each leg leveling apparatus comprising: one or more externally threaded rods connected between the leg and the frame for supporting the frame thereon, each of the one or more rods being axially moveable therebetween for adjustment to an effective height for leveling the frame relative to the leg; and apparatus for leveling the slate relative to the frame, each slate leveling apparatus comprising: a bracket for connection to the frame; a threaded member supported in the bracket and extending axially upwardly therethrough, an effective height of the member being adjustable axially along a z-axis within the bracket; and a contact plate for supporting the playing surface thereon in a substantially level orientation, the contact plate supported at a top end of the threaded member for tilting about an x-axis and a y-axis, the plate being moveable thereabout for freely orienting the contact plate relative to an underside of the playing surface so as to substantially maintain full contact with the playing surface when the effective height of the threaded member is adjusted to position the plate at the underside of the playing surface, wherein the effective height of each of the one or more rods of each leg leveling apparatus are adjusted so as to level the frame supported on the legs; and thereafter the effective height of the threaded member of each of the slate leveling apparatus is adjusted for leveling the slate relative to the frame.
 7. The system of claim 6 wherein the contact plate is connected to the top end of the threaded member through a ball and socket connection.
 8. The system of claim 6 wherein the apparatus for leveling the frame further comprises: three threaded rods connected between each leg and the frame.
 9. The system of claim 6 wherein the threaded rod is rotated for adjusting the effective height.
 10. The system of claim 6 further comprising: a mounting bracket for connecting each of the legs to the frame, the leg leveling apparatus extending through the mounting bracket, the mounting bracket having one or more upstanding members for connecting to the frame.
 11. The system of claim 10 wherein the mounting bracket conforms to a corner of the frame.
 12. The system of claim 11 wherein the mounting bracket is a unitary bracket having an upstanding member conforming to the corner of the frame and a substantially horizontal plate supported on a top of the leg, the leg leveling apparatus extending through the substantially horizontal plate.
 13. The system of claim 6 further comprising at least an internally threaded socket fit within a bore in a top of the leg for accepting the threaded rod therein, the rod being threaded into the socket for adjusting the effective height of the rod.
 14. The system of claim 6 wherein the playing surface supported in the frame is a billiards table. 